In battle field, the main purpose is to keep your base alive as long as you can by building the defense efficiently. There’re 10 kinds of defense units. Choose where and which to build to block both air and land enemies away from your base. Once the base health comes to zero, the battle is lost. Destroying your enemy gives the defense units EXP points. The more one destroyed, the higher rank it will be. Equipped with medals from enemy, defense units gain more abilities: stun, teleportation, money steal, life steal, heavy damage, fast speed, wide range, critical hit, more medals or more exp points. Enemies come in waves and from all directions. The time you last on the battle field depends on your wisdom!